The purpose of this program-project is to investigate the structure of viruses and the relationship of structure to biological function. The main lines of investigation have to do with the polymerization- depolymerization of the proteins of several strains of tobacco mosaic virus, with the reconstitution of tobacco mosaic virus, with the study of the structure of TMV-RNA and related model substances, with the loss of biological activity, with the structure of the coat proteins of bacteriophage, with the structure and orientation of nucleic acid in bacteriophage, other viruses and spermatozoa.